Problems fitting an XO crankset to my 950 Element .

For my 2012 950 Element 29'r , I just got an XO 2x10 crankset to replace the stock X9 unit .
The big ring on the XO is a 42 while the X9's is a 38 .
The XO's 42 is touching the front derailleur cage and wont
fully insert into the BB .
Do I need a different derailleur or just a smaller big ring .
The XO's and X9's sprockets are not interchangeable either .

SRAM has specific FD's for every chainring combo(26/39 and 28/42). They also have specific top and bottom pull FD's in the same direct mount version. It makes ordering a coffee at Starbucks a simple process by comparison.

And they have a horribly complicated chart if you are changing between SRAM cranks.